Pain scales are tools used to measure and assess a patient’s pain, usually for diagnostic purposes. Since pain is subjective, pain scales try to help patients effectively convey how severe their pain is. Each pain scale has its pros and cons are given different situations and diagnostic circumstances.
Like one-dimensional pain scales, some scales prioritize a simple and quick classification of the pain to help patients convey their distress and receive appropriate help. Others allow for a more in-depth and helpful classification in cases where doctors and their patients have the time to work through a multidimensional pain scale and better identify the pain’s location and nature.
Pain Scale Types
Pain scales can typically be classified as either one-dimensional or multidimensional.
- One-dimensional pain scales utilize a single element to help patients describe their pain intensity, such as a number, a color on a gradient, or a symbol.
- Multidimensional pain scales ask multiple questions to ascertain more details about the pain, including how it feels (stinging vs. burning), what regions of the body are most affected, how the patient is expressing their pain, and more.
One-Dimensional Pain Scales
Most one-dimensional pain scales use either numbers or faces, but there are other variations as well. Standard one-dimensional pain scales include:
Numerical Pain Scale/Numeric Rating Scale
Numerical pain scales are usually numbered 0 through 10, with zero being “no pain” and 10 being “worst pain.” Numerical pain scales are useful for determining the pain’s urgency but are also often the least descriptive pain scales. One exception is the Mankoski scale, which elaborates on the numeric rating scale by providing a short description for each number (rather than a 10-point gradient between no pain and worst pain), so patients can give a more accurate score.
Visual Analog Pain Scale
These usually use a gradient or line to give patients greater freedom to describe their pain by picking a point on the gradient or line without an associated number. A centimeter ruler is then used to determine the number that would roughly correspond to classify the pain.
Categorical Pain Scale
These use some other indicator to describe the intensity of the pain from none to worst, usually either through descriptive words (such as mild or moderate pain, to excruciating, severe, extreme/very severe pain) or, as commonly used with children, faces. The well-known Wong-Baker FACES scale is used for children and adults alike and uses six different faces (one for zero and each even number until 10) to help classify a patient’s pain. The scale also uses a color gradient from green through yellow and red.
Multidimensional Pain Scales
Multidimensional pain scales are more complicated but can help provide a more accurate and comprehensive overview of a patient’s pain, which is very helpful in complex or chronic pain cases. Some standard multidimensional pain scales include:
Some patients cannot effectively choose or describe their pain levels when directed to – infants. For example, need a completely different pain scale concept to help those responsible for neonatal care understand how an infant might be feeling. The CRIES Scale utilizes a nurse or physician-provided intensity rating of 0 through 2 on five different factors to assess an infant’s pain score. These factors are:
- Oxygenation Requirement
- Increased Vital Signs
- Facial Expression
The total score is meant to represent the infant’s potential pain levels.
McGill Pain Questionnaire
The McGill Pain Questionnaire is a more intensive pain scale that utilizes a total of 78 descriptive words, asking patients to mark words that they identify with their pain and mark where they feel pain (on an outline of the human body). A score is assigned based on the total number of words selected.
FLACC stands for:
- Facial expression
- Activity level
These five factors are rated 0 through 2, adding up to a total score. This scale is used with children who are otherwise uncooperative or cannot read yet but may also be used for adults who cannot verbally communicate.
While it might seem like a third acronym scale, the COMFORT Scale is based on nine factors, rated 1 through 5. They include:
- Alertness is given a score of 1 for deep sleep, 2 for light sleep, 3 for drowsiness, 4 for alertness, and 5 for high alertness.
- Calmness is rated with a score of 1 for complete calmness, and higher ratings given for increased anxiety and agitation.
- Respiratory distress is rated based on how much a person’s breathing reflects pain, with agitated breathing given higher ratings.
- Crying is given a score of 1 for no crying, and higher scores for moaning, sobbing, or screaming.
- Physical movement is given a score of 0 for no movement, which can be a sign of less pain or of illness. A score of 1 or 2 indicates some movement, and higher scores indicate vigorous movements.
- Muscle tone is rated at a score of 3 if it is normal, with lower scores indicating diminished muscle tone and higher scores indicating increased tone or rigidity.
- Facial tension is rated at a score of 1 for a completely normal, relaxed face, and given higher ratings for signs of facial muscle strain.
- Blood pressure and heart rate are rated with respect to the normal baseline. A score of 1 indicates that these measures are below the baseline (abnormal), and a score of 2 indicates they are at baseline, while higher scores are given for elevated (abnormal) levels.
A minimum pain level (no pain) would be a score of nine, and a maximum pain level would be a score of 45. The COMFORT Scale is usually used for intensive care patients, children, and cognitively impaired adults.
Brief Pain Inventory
The Brief Pain Inventory includes 15 questions on how a patient’s pain has impacted their sleep, work, interactions with others, walking, and general quality of life. Patients are asked to circle a number between zero and 10, where zero means “does not interfere,” and ten standards “completely interferes.” Much like the McGill questionnaire, an outline of the human body from both front and back is included to help patients pinpoint where they feel pain.
When Pain Scales Are Used
Some pain scales specialize in helping doctors identify and prioritize treatment in emergencies. Others help facilitate communications between a doctor and their patient for complex and chronic pain conditions. Different pain scales serve different uses and recognizing when they are relevant is an essential part of the job. Some pain scales help physicians classify pain levels in cases where patients might be unable to verbally communicate their pain, as with:
- Young children
- And incapacitated or impaired adults
Pain scales are helpful not only for diagnostic purposes but better to facilitate communications between a patient and their physician. Hence, patients have a systematic and useful way of conveying something as subjective as pain to their doctors without feeling lost or frustrated.